Palladium coated implant

Abstract

The present invention provides methods and devices which use a palladium source enriched in Pd-102 and depleted in Pd-108 and Pd-110 to coat the body of a medical device. Whereas prior devices, which include palladium throughout the volume of the body, require the use of highly enriched palladium sources to counteract the effect of absorption of radiation by palladium and other metals in the body, devices wherein palladium is located primarily on the surface of the body more efficiently deliver therapeutic radiation to the target tissue, and thus can employ less highly enriched palladium sources. Such palladium sources are significantly less expensive than highly enriched sources, thereby greatly reducing the cost of devices and methods which use such a coating of palladium.

What is claimed is:  
     
       1. An activatable medical device, comprising 
       a body, and  
       a layer of non-radioactive palladium disposed on said body, said layer being enriched in Pd-102 relative to naturally occurring palladium, substantially free of Pd-110, and comprising less than about ten percent Pd-102.  
     
     
       2. The device of claim  1 , wherein the body is substantially free of isotopes which significantly thermal neutron activate to radioisotopes having half-lives between about 16 hours and about one million years. 
     
     
       3. The device of claim  1 , further comprising a biocompatible coating disposed on the layer of palladium. 
     
     
       4. The device of claim  3 , wherein said biocompatible coating comprises titanium. 
     
     
       5. The device of claim  4 , wherein the biocompatible coating has a thickness of from about 0.0025 cm to about 0.0125 cm. 
     
     
       6. The device of claim  1 , wherein the layer of palladium is less than about 10 microns thick. 
     
     
       7. A method for making a medical device, comprising 
       providing a body, and  
       disposing on the body a layer of non-radioactive palladium, said layer being enriched in Pd-102 relative to naturally occurring palladium, substantially free of Pd-110 and comprising less than about ten percent Pd-102.  
     
     
       8. The method of claim  7 , further comprising exposing the body and the layer of palladium to a source of thermal neutrons, thereby activating said palladium. 
     
     
       9. The method of claim  7 , wherein the body is substantially free of isotopes which thermal neutron activate to form radioisotopes having half-lives between about 16 hours and about one million years. 
     
     
       10. The method of claim  7 , further comprising a biocompatible coating disposed on the layer of palladium. 
     
     
       11. The method of claim  10 , wherein said biocompatible coating comprises titanium. 
     
     
       12. The method of claim  11 , wherein the biocompatible coating has a thickness of from about 0.0025 cm to about 0.0125 cm. 
     
     
       13. The device of claim  7 , wherein the layer of palladium is less than about 10 microns thick.